2N6497

http://onsemi.com

3

Figure 3. Thermal Response

t, TIME OR PULSE WIDTH (ms)

1.0

0.01

0.01

0.7

0.5

0.3

0.2

0.1

0.07

0.05

0.03

0.02

0.02

0.05

0.1

0.2

0.5

1.0

2.0

5.0

10

20

50

100

200

1000

500

RθJC(max) = 1.56°C/W

D CURVES APPLY FOR POWER

PULSE TRAIN SHOWN

READ TIME AT t1

TJ(pk) - TC = P(pk) RθJC(t)

P(pk)

t1

t2

DUTY CYCLE, D = t1/t2

D = 0.5

SINGLE PULSE

0.2

0.05

0.1

0.02

0.01

SINGLE

PULSE

0.03

0.3

3.0

30

300

BONDING WIRE LIMITED

THERMAL LIMIT (SINGLE PULSE)

SECOND BREAKDOWN LIMIT

20

Figure 4. Active–Region Safe Operating Area

2.0

10

20

500

TC = 25°C

0.2

5.0

0.5

VCE, COLLECTOR-EMITTER VOLTAGE (VOLTS)

10

70

1.0

0.02

dc

5.0

100

7.0

CURVES APPLY BELOW RATED VCEO

5.0 ms

1.0 ms

100 µs

0.1

0.05

30

50

300

200

There are two limitations on the power handling ability of

a transistor: average junction temperature and second

breakdown. Safe operating area curves indicate IC – VCE

limits of the transistor that must be observed for reliable

operation; i.e., the transistor must not be subjected to greater

dissipation than the curves indicate.

The data of Figure 4 is based on TC = 25_C; TJ(pk) is

variable depending on power level. Second breakdown

pulse limits are valid for duty cycles to 10% provided TJ(pk)

v 150_C. TJ(pk) may be calculated from the data in

Figure 3. At high case temperatures, thermal limitations will

reduce the power that can be handled to values less than the

limitations imposed by second breakdown. Second

breakdown limitations do not derate the same as thermal

limitations. Allowable current at the voltage shown on

Figure 4 may be found at any case temperature by using the

appropriate curve on Figure 6.

Figure 5. Turn–Off Time

IC, COLLECTOR CURRENT (AMP)

VCC = 125 V

IC/IB = 5.0

TJ = 25°C

ts

tf

10

7.0

5.0

3.0

2.0

1.0

0.7

0.5

0.1

0.3

0.2

0.05

5.0

1.0

0.1

2.0

0.07

3.0

0.3

0.2

0.5 0.7

100

80

60

20

0

0

20

40

60

80

100

120

140

160

Figure 6. Power Derating

TC, CASE TEMPERATURE (°C)

THERMAL DERATING

SECOND BREAKDOWN DERATING

40